An electrochemical microsensor based on molybdophosphate complex for fast determination of total phosphorus in water

Abstract

This work mainly describes an electrochemical microsensor based on the reduction of molybdophosphate complex for fast determination of total phosphorus (TP) in water. Compared with the traditional methods for phosphate detection reported previously that used bulk electrodes, this microsensor responds faster, and can be applied to TP detection rather than merely phosphate. Calibration of phosphate has been performed with standard solutions prepared with KH <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> PO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> with pH adjusted to 1.0. The limit of detection (LOD) is 0.66µmol/L, and linear range is 1∼500µmol/L. The sensitivity is −0.657 nA per µmol/L (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> =0.994). Detection of TP was also carried out in digested TP standard solutions, and the results were consistent with the nominal value of phosphorus concentration.